Use ZSTEP to incrementally execute a routine or series of routines. Execute any GT.M command from Direct Mode at any ZSTEP pause. To resume normal execution, use ZCONTINUE.

Note that ZSTEP arguments are keywords rather than expressions. They do not allow indirection, and argument lists have no utility.

ZSTEP actions that include commands followed by a BREAK perform some action before entering Direct Mode. ZSTEP actions that do not include a BREAK perform the command action and continue execution. Use ZSTEP actions that issue conditional BREAKs and subsequent ZSTEPs to do such things as test for changes in the value of a variable.